The modern consumer of processed food is seeking to achieve a high quality food product with a minimum of preparation. This desire has led to the widespread utilization of microwave ovens in the average American household and the use of microwave ovens to heat machine vendable food products. While microwave energy will rapidly heat most food products, not all microwave heated products are able to deliver the same quality as is characteristic of the more traditional conduction oven heated counterpart. This lack of quality is quite prevalent in the area of microwave reheated baked goods.
Problems have arisen with the use of microwave energy for heating traditional yeast-raised wheat-based food products such as bread and roll products. Traditional bread and roll products become impalatable after short exposures to microwave energy. The term palatable or palatability refers to the eating quality of food products. Palatable food products are agreeable to the taste and possess an appetizing appearance and texture.
Upon exposure to microwave energy, the crust of traditional bread and roll products becomes extremely tough and/or soggy as water present within the baked good migrates to the surface crust but does not evaporate off. The crust of such microwave exposed products may become so tough that it is difficult to tear such products. The bread product itself may become soggy or develop hard lumpy portions. The crumb of the products becomes rubbery and gummy and is difficult to chew. Consequently, traditional bread and roll products, upon exposure to microwave energy, are not palatable.
U.S. Pat. Nos. 4,560,559 and 4,463,020 to Ottenberg discuss the preparation of yeast-raised wheat-based food products having improved resistance to deterioration caused by microwave heating. The earlier patent accomplished this improvement by the incorporation of from about 5 to about 60 percent by weight of the weight of the wheat flour of a long-grain rice flour. The later patent accomplished the improvement by the incorporation of a similar amount of a rice starch, corn starch or wheat starch possessing an average crystal size less than 20 microns. Both Ottenberg patents disclose that the food product containing the starch should not be in a frozen state when reheated by microwave energy and if a frozen product is produced it should be defrosted or thawed before being heated in a microwave oven. Additionally, the later patent teaches that the incorporation of potato starches do not improve the microwaveability of yeast-raised wheat-based food Products.
There is a need in the food science art to produce a shelf-stable, refrigerated or frozen baked good which will substantially retain its palatability upon microwave heating. In the case of the frozen baked good to be microwave-heated, it would be beneficial if such a product could be taken out of the freezer and directly heated by microwave energy without the need of defrosting or thawing prior to microwaving.